Table 3. Influenza viruses characterised by clade and study site, Europe, influenza season 2017/18 (n = 886).

	Clade	ES a		UK		EU-PCb		DKc
		n	%	n	%	n	%	n	%
Total influenza A(H1N1)		n = 142		n = 20		n = 469		n = 113
Sequenced		28	100	10	100	25	100	23	100
A/Michigan/45/2015	6B.1	28	100	10	100	25	100	23	100
Total influenza A(H3N2)		n = 233		n = 174		n = 229		n = 144
Sequenced		51	100	59	100	43	100	51	100
A/HongKong/4801/2014	3C.2a	20	39	46	78	27	63	36	71
A/Singapore/INFIMH-16–0019/2016	3C.2a1	31	61	10	17	16	37	15	29
A/Switzerland/9715293/2013	3C.3a	0	0	3	5	0	0	0	0
Total influenza B		n = 1,022		n = 209		n = 1,469		n = 625
Sequenced		164	100	116	100	207	100	109	100
B/Yamagata		136	83	116	100	198	96	109	100
B/Phuket/3073/2013	3	136	100	0	0	198	100	109	100
B/Victoria		28	17	0	0	9	4	0	0
B/Norway/2409/2017	1A Δ(K162, N163)	20	71	0	0	5	56	0	0
B/Brisbane/60/2008	1A	8	29	0	0	4	44	0	0

^a 50 specimens from ES are also included in EU-PC data.

^b The specimens sequenced from Spain are originating from the entire National Influenza Surveillance System between weeks 44/2017 and 03/2018.

^c Sequence information is based on a sub-sample of influenza-positive samples received for surveillance at the National Influenza Center Denmark from week 40/2017 to 4/2018.